JPH08192048A - Carrier catalyst being suitable for ammoxidation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously improve low flow properties, low wearabilities, and low transfer properties by providing a support material containing aluminum oxide, silicon dioxide, and titanium dioxide, and/or zirconium dioxide and an active material containing vanadium and antimony in the form of oxides, as essential components. SOLUTION: A support material is manufactured by a method wherein the solution or suspension of each of compounds such as aluminum, silicon, titanium, and/or zirconium is spray-dried and resultant powder is oxidized in a gas flow containing oxygen at 500-1200 deg.C. Particles of the support material are spherical or approximately spherical and the bulk density thereof is from 0.6 to 1.2 kg/l. The amount of vanadium, calculated as metal, is in the range of 0.5-10 wt.%. The amount of antimony, calculated as metal, is 0.5-10 wt.%. Thus, low flow properties, low wearabilities, and low transfer properties, which are not preferable as a catalyst for use in flow process, can be improved simultaneously.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to (a) a carrier material containing aluminum oxide, silicon dioxide, titanium dioxide and / or zirconium dioxide, and (b) vanadium and antimony as oxides in the form of oxides. The present invention relates to a carrier catalyst for ammonooxidation, comprising:

The invention also relates to a process for the preparation of such supported catalysts and the uses or processes used for ammonooxidizing iso and heteroaromatic alkyl compounds to prepare the corresponding nitriles.

C such as toluene, xylene, picoline
₁ -C ₄ alkyl - ammoxidation of iso and heteroaromatic compounds are conventional way to produce the corresponding aromatic nitriles industrially. The reaction is generally carried out in the gas phase using a supported catalyst containing, in addition to vanadium, other elements such as antimony, chromium, molybdenum, phosphorus in the form of oxides. As the carrier, aluminum oxide, silicon dioxide, titanium oxide or zirconium dioxide or a mixture of these oxides is mainly used.

The intensely exothermic ammonooxidation is carried out in fluidized bed reactors which are technically customary, so that high demands are made on the catalyst with regard to fluidity, attrition resistance and heat transfer. However, this requirement is not fully satisfied. In particular, the wear resistance of this type of catalyst is strongly desired. Attrition results in a fine powder of the catalyst, which can lead to undesired continuous reactions outside the fluidized bed zone.

Good heat transfer is achieved by the high bulk density of the catalyst, which is limited by the requirement for flowability.

The production of catalysts has already been carried out by a known method for a long time, but this production method also gradually changes with the passage of time. According to the method described in each of Nishi unique application No. 2810856 and European patent application No. 222249, aluminum oxide is calcined at 900 ° C., crushed and sieved. The desired particle size powder is impregnated with the catalytically active solution, the solvent is evaporated off, the remaining mixed material is dried, calcined under oxidizing conditions and ground again. A method similar to this is also described in Nishi Unique Application No. 1643630 (US Pat. No. 3,637,797).

The needle-like powder thus obtained requires an extremely high-cost technique for use in the fluidized bed process because of its low bulk density (about 0.5 kg / l). Also, such catalyst powders are inferior in heat transfer due to their low bulk density.

[0008]

The problem to be solved by the present invention is, therefore, a drawback of the above-mentioned prior art, namely, low fluidity, low abrasion and low conductivity which are not preferable as a catalyst used in a fluidized bed process. Is to improve at the same time.

[0009]

However, it has been found that the above-mentioned problems can be solved by a supported catalyst and a method for producing the same, which are regulated in the claims. This catalyst is particularly suitable for ammonooxidation.

Spherical or nearly spherical supported catalysts are known per se and are commercially available (in the case of aluminum oxide supported catalysts, various shapes are available, for example under the trademark Puralox® by Condea-Chemie). It is commercially available). However, such a form has not been used as a catalyst for ammonooxidation.

Suitable spherical particles have an average shape factor, F
> 85% is preferred. This factor F is F =
It can be defined as (U ₂ ) ² / (U ₁ ) ² . U ₁ means the size of the particle cross section, and U ₂ means the circumference of the same cross section Q. The minimum factor requirement is met when the particle cross section does not correspond to a relatively small number, as statistically confirmed.

The carrier material is prepared by subjecting a solution or suspension of a compound of aluminum, silicon, titanium and / or zirconium to a spray-drying treatment and treating the resulting powder with an oxide in an oxygen-containing gas stream at 500 to 1200 ° C. And can be manufactured. During this spray drying, the desired particle size and bulk density are adjusted in a manner known per se.
The bulk density of the carrier material particles according to the invention is from 0.6 to 1.2 kg / l, especially from 0.7 to 1.0 kg / l.
It is preferably in the liter range.

In order to spray-dry a solution of the respective compound to form spherical particles, this compound is, for example, an alcoholate such as ethanolate, isopropylate, a carboxylate such as acetate, sulphate or nitrate. Preferred as the suspension compound are hydroxide and oxide hydrate.

The calcined support material is impregnated with a solution or suspension of the catalytically active material compound, dried in a manner known per se and recalcined in a stream of air. Drying temperature is 100-200 ℃, calcination temperature is 400-70
0 ° C is preferred.

For impregnation, aqueous solutions or suspensions of catalytically active constituent compounds are preferred, but in principle any liquid can be used. The impregnating solution or suspension is preferably used in an amount no more than that which is accepted by the carrier material. If too much, on drying, agglomerates form which have to be ground again and lead to particles which do not have the desired spherical shape. The impregnation treatment can be carried out in multiple stages after each intermediate drying treatment.

The amount of vanadium, calculated as metal, is generally 0.5 to 10% by weight, preferably 1.0 to 6, especially 1.5 to 5% by weight, in the active catalyst,
Antimony is similarly calculated as a metal, 0.5 to 10
% By weight, preferably 0.5 to 8, especially 0.5 to 6
It is contained by weight%.

In particular, the catalysts suitable for ammonooxidation preferably additionally contain 0.01 to 2.0% by weight, calculated as metal, of cesium and / or rubidium. In addition, it is advantageous to contain 0.05 to 1.5% by weight of tungsten, calculated as metal.

All of these amount ratios are ratios with respect to the total amount of the catalyst.

The active component of the catalyst according to the invention may contain further constituents as indicated in the literature on ammonooxidation, namely titanium, iron, cobalt, nickel, manganese or copper.

For impregnating the carrier material, the active ingredient is converted into its salt,
In particular, it is preferably used in the form of an aqueous solution of an organic acid salt which decomposes without leaving a residue during oxidative calcination. Preference is given to using oxalate, in particular in the case of vanadium, especially tartrate in the case of antimony, which can also be used in the form of a mixed salt with ammonium ions. To form such a solution, the metal oxide is dissolved in acid. Tungsten is preferably used in the form of a complex compound with tartaric acid, oxalic acid or citric acid.

The catalyst according to the invention is particularly suitable for ammonooxidation in a fluidized bed. This fluidized bed technology itself is well known and will not be described in further detail.

This catalyst is preferably used, in particular, when mono- or polyvalent isoaromatic or heteroaromatic nitriles are prepared from the corresponding alkyl compounds, especially methyl compounds.

In particular, o-phthalodinitrile from o-xylene, isophthalodinitrile from m-xylene,
Ammonooxidation for the production of terephthalodinitrile from p-xylene, benzonitrile from toluene and nicotinic acid nitrile from β-picoline is important.

In the case of xylene, the ammonooxidation of the primary methyl is carried out earlier than the secondary methyl, so that the partial ammonooxidation product is easily obtained, as is the case when p-methylbenzonitrile is obtained from p-xylene. .

The aromatic parent compound may have a group inert under ammonooxidation conditions, for example, a substituent such as halogen, trifluoromethyl, nitro, amino or cyano. Even a group which is not inactive may have a preferred substituent group such as aminomethyl or hydroxymethyl group under ammonooxidation conditions.

The starting compounds are placed in a mixed gas stream of ammonia and an oxygen containing gas such as air. The quantity proportion is adjusted to 0.1 to 25% by volume, in particular 0.1 to 10% by volume.

The catalyst of the present invention is 0.0 per hour per kg of catalyst.
The catalyst loading is shown where 1 to 1 kg of starting compound can be used. This is a significant advantage in that the fluidized bed is constantly maintained over long operating times and therefore does not require expensive adjustments. The formation of undesired by-products is also suppressed, and the yield of the desired product is correspondingly increased significantly.

Example 1 (Production of carrier catalyst) Form factor 0.85, bulk density 0.
8kg / liter spherical aluminum oxide Puralo
x (registered trademark) SCCa150 / 120, Condea
Chemie) 1000 g in a mixing device, 351.4 g distilled water, 150 g 25% strength NH.
₃ solutions, 65.5 g antimony (III) oxide, 5
6.2 g vanadate (90% vanadium (V) oxide), 6.5 g cesium, 150 g tartaric acid and 1
Aqueous solution 9 consisting of 52.3 g of oxalic acid dihydrate 9
It was impregnated with 31.9 g. The solution was completely adsorbed. The catalyst material obtained was dried at 120 ° C. and calcined in a stream of air at 580 ° C.

(Ammonoxidation of o-xylene) The above catalyst (0.75 liter) was loaded, and the diameter was 6 cm and the height was 1.
3% by volume in a 20 cm laboratory fluidized bed reactor
O-xylene was reacted at a temperature of 470 ° C. in a mixed gas stream consisting of 3% o-xylene, 12% by volume oxygen and 85% by volume ammonia. This gives 95.3
O-Phthalodinitrile was obtained with a% o-xylene conversion of 64.6% yield (vs. o-xylene).

Comparative Example (Production of Supported Catalyst) A catalyst was produced by the same method as described above. However, the aforementioned European patent application 222222
The carrier material particles were needle-shaped and had a bulk density of 0.5 kg / liter, as described in Japanese Patent Application Laid-Open Publication No. 2004-242242.

(Ammonoxidation of o-xylene) The reaction was carried out in the same manner as above, but the conversion of o-xylene was 95.
8%, the yield of o-phthalodinitrile is 62.8% (vs. o.
-Xylene).

Example 2 Spherical aluminum oxide particles having a bulk density of 0.8 kg / liter (Puralox® SCCa 150/12)
0, Condea-Chemie) 1000 g in a mixer, 351.4 g distilled water, 150 g ammonia 25% solution, 65.5 g antimony (II).
I) oxide, 56.2 g of vanadic acid (90% by weight,
The vanadium (V) oxide was impregnated with 931.9 g of an aqueous solution consisting of 12.5 g cesium nitrate, 150 g tartaric acid and 152.3 g oxalic acid dihydrate. In the above aqueous solution, 13.8 g of ammonium paratungstate ([NH ₄ ] ₁₀ H ₂ W ₁₂ O ₄₂ × 5H ₂ ) was previously added to 50 g of tartaric acid and 200 ml of water.
A solution in which O) was dissolved was added. 5 impregnated catalyst materials
It was calcined in an oven at 80 ° C for 2 hours. It was confirmed by chemical analysis that the tungsten content was 1.0% by weight.

(O-xylene ammonoxidation) In a laboratory fluidized bed reactor having a diameter of 6 cm and a height of 120 cm charged with 600 g of the above catalyst, 3.2 vol% of o-xylene (128 g / h), 12 vol. The o-xylene was reacted at a temperature of 470 ° C. in a mixed gas stream consisting of% oxygen and 85% by volume ammonia. The amount of o-xylene to be fed was limited by the coking of the catalyst. This is because feeding a large amount of o-xylene causes the reaction to reverse. In this example, the o-xylene conversion rate was 9
5.7%, the yield of phthalodinitrile is 65.0% (vs o)
-Xylene). Therefore, for 100 g of catalyst,
This means that 100.4 g of phthalodinitrile was obtained every hour.

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[Procedure amendment]

[Submission date] August 28, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 7

[Correction method] Change

[Correction content]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Frank-Friedrich, Pape Germany, 67259, Kleinide Desheim, Freichel-von-Gagern-Strasse, 24 (72) Inventor Ulrich, Köhler Germany, 68259, Mannheim, Osterbrucker, Strasse, 19 (72) Inventor Reiner, Becker Germany, 67098, Bad, Durkheim, Im, Hazeneck, 22 (72) Inventor Peter, Weidrich Germany, 68159, Mannheim, Jott 7, 2

Claims (17)

[Claims] 1. (a) Aluminum oxide, silicon dioxide, titanium dioxide and / or, characterized in that the support material is spherical or nearly spherical and has a bulk density of 0.6 to 1.2 kg / liter. A carrier catalyst for ammonooxidation comprising a carrier material containing zirconium dioxide and (b) an active material containing vanadium and antimony in the form of oxides as essential constituents. 2. Support catalyst according to claim 1, characterized in that the active material (b) additionally contains cesium and / or rubidium in the form of an oxide. 3. A supported catalyst according to claim 1 or 2, characterized in that the active material (b) additionally contains tungsten in the form of an oxide. 4. Vanadium in an amount of 0.5 to 10% by weight, calculated as a metal, with respect to the carrier catalyst material, and 0.1.
A supported catalyst according to any of claims (1) to (3), characterized in that it contains 5 to 10% by weight of antimony. 5. Support catalyst according to claim 2, characterized in that the support catalyst material contains 0.01 to 2% by weight, calculated as metal, of cesium and / or rubidium. 6. A carrier catalyst according to claim 3, characterized in that the carrier material contains from 0.05 to 1.5% by weight of tungsten, calculated as metal. 7. A method for producing a supported catalyst according to any one of claims (1) to (6), wherein the spherical or substantially spherical support material is a vanadium compound and a vanadium compound, and optionally a tungsten compound. And a solution or suspension of a cesium compound and / or a rubidium compound, the excess liquid is separated off from the resulting mixture, dried and calcined under oxidizing conditions. 8. Process according to claim 7, characterized in that vanadium is used in the form of the oxalate salt. 9. Process according to claim 7, characterized in that antimony is used in the form of the tartrate salt. 10. The method according to claim 7, characterized in that tungsten is used in the form of a complex with tartaric acid, oxalic acid or citric acid. 11. Method according to claim 7, characterized in that the calcination is carried out at a temperature of 400 to 750 ° C. 12. Monovalent oxidation of isoaromatic or heteroaromatic alkyl compounds with oxygen- and ammonia-containing gases using the catalyst according to any one of claims (1) to (6). Alternatively, a method for producing a corresponding poly- or heteroaromatic nitrile. 13. The method according to claim 12, wherein the reaction is carried out at 300 to 550 ° C. 14. The oxygen content of the gas used for ammonooxidation is 0.1 to 25% by volume.
Method according to claim (12). 15. Reaction according to claim 12, characterized in that the reaction is carried out in a fluidized bed. 16. A process according to claim 12 for producing methylbenzonitrile or benzodinitrile by ammonooxidation of xylene. 17. A process according to claim 12 for producing phthalodinitrile by ammonooxidation of o-xylene.